Shutter dissolve mechanism



Aug. 3, 1937 G. A. MITCHELL SHUTTER DISSOLVE MECHANISM Filed May 5, 1954 s Sheets-Sheet 1 1710622 62 0736 Male/ e1! Aug. 3, 1937.

G. A. MITQHELL SHUTTER DISSOLVE MECHANISM 6 Sheets-Sheet 2' g. um r J w m M ///A w 5 II. M M; .M 7:v mw %/1 J H Filed May 5, 1934 6 Sheets-Sheet 3 Aug. 3, 1937.

G. A. MITCHELL SHUTTER DISSOLVE MECHANISM Filed May 5, 1934 6 Sheets-Sheet 5 "Ilill G. A. MITCHELL SHUTTER DISSOLVE MECHANISM Aug. 3 1937.

6 Sheets-Sheet Filed May 5, 1934 r4 fi W e H a M HZ r H. ,l 6. 0 m 7 6 W H M M 1/] 2 4 Wm M 5 4 67 w 9/ w. a g m m E M m w m m m We 9 H mm H. U 4 2 2 4 9 U 5% 4 .3 w fi fl Patented Aug. 3, 1937 UNITED STATES PATENT OFFICE SHUTTER DISSOLVE MECHANISM Application May 5, 1934, Serial No. 724,193

21 Claims.

This invention relates generally to motion picture cameras, and more particularly to shutter dissolve mechanisms for motion picture mechanisms.

Motion picture cameras of professional grade are ordinarily equipped with two relatively rotatable shutter members, which are adapted to take such a position as to provide an angular opening therebetween of say 170, so as to uncover the film for substantially 170 of shutter rotation what is known as a dissolve.

when the two shutter members are rotated as one; or are adapted, by relative adjustive rotation, to reduce the angular opening therebetween down to zero, or in other words to efiect Means are commonly provided for effecting such a dissolve during photographing of a scene, either by manual or by automatic adjustment operation of the shutter mechanism.

Difiiculty is commonly encountered in such mechanisms due to a relative creep of one shutter member relativeto the other during normal operation of the camera, at which time the shutter shafts should rotate as one. Any such creep obviously means uncontrollable variations of the angular shutter opening, which, even if amounting to but a few degrees, is highly objectionable.

It is accordingly another object of the present invention to provide automatic means for positively locking the shutter members against relative rotation at all times except when either a dissolve is being effected, or the shutter opening is being increased.

The present invention provides an automatic 0 look which normally locks the dissolve mecha- Fig. 3 is a section taken on line 33 of Fig. 2, with parts of the camera broken away to show underlying parts in section;

. 4 is a section taken on line 4-4 of Fig. 1- 5 is a section taken on line 5-5 of Fig. 4 5

i 6 is a section taken on line 6-5 of Fig 7 is a section takenon line I T oi Fig. 8 is a section taken on line 8-8 of Fig. 7; Fig. 9 is a section taken on line 9-9 of Fig. 7;

Fig. 10 is a section taken on line 10-40 of Fig. 8;

Fig. 7;

Fig. 12 is a section taken on line |2I2 of Fig. 2;

Fig. 13 is an enlarged detail taken from Fig. 12, but showing the parts in a different position; and

Fig. 14 is 'a section taken on line 14-14 of Fig. 2;

The present invention here shown in a specific form applied to a specific dissolve mechanism which is incorporated in a particular type of camera; it will be understood, however, that this is for other illustrative purposes only, and that the invention in its broader aspects is not to be limited to the particular illustrative form of the invention here detailed.

The camera here shown is of a special sound insulated type, completely disclosed and claimed in my copending application entitled Sound in sulated motion picture camera, filed May 7, 1934, Ser. No. 724,351. It is characteristic of this type of camera that its film mechanism, including the drive motor, dissolve mechanism, film magazine and afocusing instrument, shifts laterally behind the photographic lens; and certain aspects of the present invention relate to dissolve mechanism control devices designed particularly for that type of camera.

In the drawings, numeral I0 designatesgenerally the exterior case of the camera, this case comprising a box-like casting ll including front and rear walls 12 and 13, respectively, side wall It having downwardly swinging door 15, side wall 16, top l1 and bottom or bed plate l8. This bed plate is adapted to be secured down to the head plate of the tripod.

The top wall ll of case II has a rectangular opening 21 through which extends the lower portion or throat of the usual camera magazine 22. A magazine compartment 23 is. removably 111011115- ed on the top of case I I around opening 2|, and is of a size and shape to accommodate the camera magazine in the two different positions of the laterally shift-able camera box 32 that carries it.

The entire case and magazine compartment is shown to be lined with a layer 26 of suitable sound Fig. 11 is a section taken on line ll-ll of plate 3., having rising from. its forward end a vertical, hollow head portion II, and a camera. box or mechanism carrier 32 located to the rear of head II and arranged to slide transversely across bed II in ways 33.

Camera base II is supported on an insulation pad II, which rests on exterior housing bed plate II, and is secured in place within the exterior housing in any suitable manner; for instance, in the manner clearly shown in Fig. 3.

The hollow camera head ll that rises from the forward end of base member 3| is closed at its forward side by a plate 42 that carries the lens mount 43, the lens mount projecting forwardly through a circular openlng N in front casing wall If. This lens mount carries the usual photographic lens, not shown. Immediately to the rear of the photographic lens and in alinement therewith there is formed in head II the usual photographic aperture, indicated at 41, this aperture extending through the rear wall ll of the hollow head ll.

The camera box 32 carries on its top the mini film magazine 22, as previously mentioned, and box 32 carries the usual film guide rollers, sprockets, and intermittent film movement mechanism, for intermittently moving the film downwardly within box 32 past aperture 41, in the focal plane of the photographic lens, these parts all being well known and requiring no present illustration.

Mounted on the side of camera box 32 at the level of photographic'aperture 41 is a focusing tube 52. The forward end of this focusing tube comes closely adjacent the rear surface of camera head Ii when camera box 32 is moved to the right on bed 30 (viewing the camera from the rear), and by such movement the forward end of the focusing tube is brought into register with 40 the photographic aperture 41 in head 3| and thus into alinement with the photographic lens. In this position the focusing tube alines with an eye piece I4 which is permanently mounted in the rear wall I! of the exterior camera case, this eye piece being mounted in permanent optical alinement with aperture 41 and the photographic lens. The other camera box position, indicated in Figs. 4 and 12, is the "take" position, with the film within the camera box alined with aperture l1 and the photographic lens, and the focus- 1 3g tube 5! moved out of alinement therewith. When the camera box is moved from the illustrated take" position to a position with the focusing tube alined with aperture I1 and with its eye-piece I4, then the image normally formed on the film may be viewed through eye piece 54 and the focusing tube, and at this time the photographic lens may be accurately focused. The camera box is then shifted back to the position of Figs. 4 and 12 for taking, and the image is sharp on the film.

For the purpose of so shifting the camera box between the taking and focusing positions described, the underside of said box is provided with a pair of racks II, with which mesh spur gear I on a shaft 8! that extends outwardly through the rear wall If of the exterior housing, and has on its outer end an operating handle I (Figs. 3 and 4). Rotation of this handle ll causes gears ii to act through racks II to shift the camera box from one position to the other.

The camera motor is designated at 85, its housing. being affixed to the side of camera box 31 (Figs. 4 and i2) so that the camera motor shifts (Figs. 7, 8, 10, and 11).

with the transverse movement of the camera box. The motor shaft it has on its forward end a spiral gear i! (Fig. 1) meshing with a spiral gear I on a transverse shaft 69 that drives the usual intermittent film mechanism (not shown). Shaft 9 also drives the shutter mechanism and has for this purpose a spiral gear II (Fig. 5) meshing with a spiral gear H which is mounted fast on the forward end of hollow shutter shaft 12. Shaft 12 is shown in Fig. 5 to be journaled in suitable bearings 13, H, and 15 supported by camera box 32. On the extreme forward end of hollow shaft 12 is the usual shutter ll. Mounted to rotate within hollow shaft 1! is an inner shaft II, and mounted on the forward end thereof is a shutter leaf 8!. These shutter members It and I2 rotate within an annular recess 84 sunk in the front face of camera box forward wall 32b, this recess being enclosed by a cover plate I! which has an aperture l6 registering with photographic apertures 41 of camera head II.

Shutter members II and 82, which are of conventional form, will be understood to be mounted to rotate between the photographic aperture and the film within camera box 32. These shutter members are adapted to take such a relative position as to provide substantially a 170 an-.

gular opening therebetween, so as to uncover the film for substantially 170' of rotation when shutter shafts I2 and ii are rotated as one; or, by relative adjustive rotation of said shafts, to reduce the angular opening between the shutter members down to zero, or in other words to effect what is known as a dissolve. In Fig. 6 the shutter members are shown during the course of such a dissolve, the shutter opening 0 being reduced to approximately Fastened on hollow shutter shaft 12, immediately to the rear of camera box rearward wall 320, is a gear sleeve 90 (Figs. 5 and 7), the forward end of which is formed as a worm Si, and the rearward end of which is journaled in a bearing 52 carried by mounting casting 93 secured to camera box 32. The rearward end of inner shutter shaft II has a screw section 94, andmounted to work thereon is a nut member 85. This nut member 95 is fast within a sleeve 86 which slidably fits the bore of gear sleeve Sll, and carries studs I! which project outwardly through longitudinal slots 9| in sleeve SI. The outer ends of studs 81 engage in apertures 99 in a sleeve III which is slidably mounted on sleeve 80. This sleeve III is embraced at its ends by and is rotatable within a cylindric carrier Ill, the lower side of which has a downwardly projecting gear portion or rack I". This carrier member III is constrained against rotation by a way Ill formed in member ll (Fig. 8) which receives and guides said gear projection I" for longitudinal movement. Gear portion I" is formed with spiral gear teeth and the latter mesh with a spiral gear segment I". Fast with this gear segment is a depending arm ill, to the lower end of which is pivoted one end of a link ill, the other end of which is pivoted to a vertically movable rack Ill (Figs. 7, 8, i0, 11, i2 and 13).

This rack ill moves vertically in a vertical guide groove or way Ill formed in the outer surface of a vertical supporting member III which is mounted on camera wall 320, the rack being confined in said way by means of a plate Ill mounted on the outer surface of member III The lower portion of cover plate H4 is formed with a longitudinal slot member IOI.

II which passes the pivot connection between link I08 and rack IIO.

This rack IIO has on one edge rack teeth I which are constantly in mesh with a spur gear I2 I, which gear is fast on a rearwardly extending hollow shaft I22 journaled in said mounting casting 63. The rearward end of shaft I22 has an integrally formed head I23, having in its rearward surface an off center aperture I24 (Figs. 12 and 13). Head I23 carries a pointer I25 which is adapted to move through substantially 170 of arc over a calibrated shutter-opening scale I26 inscribed on a plate I21 carried bymounting member 93. Journaled in and longitudinally slidable through a bore I30 in rear housing wall I3 is a shaft I3I, the inner end of which carries a crank disc I32 having a crank pin I33, said crank disc and pin being adapted to be received within a countersink I34 formed in the inner surface of wall I3 (Fig. 12). Shaft I3I normally carries crank disc I32 and pin I33 in the latter position by reason of a coil spring I36 placed around said shaft in a counter bore I31, which spring acts outwardly against a collar I38 on shaft I3 I. The exterior end of shaft I3I carries a manual operating crank I40.

Shaft BI is so located in camera housing wall I3 as to be concentric with shaft I22 whenthe camera box 32 has been moved to the take position indicated in Figs. 12 and 13. Crank pin I33 on shaft I3I is so arranged that at a time when the camera box is in the position of Fig. 12, it may be drivingly engaged with aperture I24 by iorcing crank I40 and shaft I3I inwardly against the force of spring I36 and turning the crank until the pin finds the aperture. This engagement having been made, turning of crank I40 causes rotation of shaft I22 and gear I2I, thereby moving rack IIO up or down, depending upon the direction in which the crank is turned. Such movement of rack IIO acts through link I08 and arm I01 to rotate spiral gear segment I06, which in turn acts on spiral gear element I02 to cause longitudinal translation of carrier The rotating sleeve I00 embraced and carried by member IOI is thus caused to move longitudinally on gear sleeve 90, and in so doing acts through stud 91 to move nut member 95 forwardly.or rearwardly within the bore of the gear sleeve. Since the nut member is constrained against relative rotation within the gear sleeve, this longitudinal movement of the nut member causes rotation of the screw element 94 relative to gear sleeve 90. and consequently relative rotation of shaft 6| within hollow shaft 12. Thus by this operation the opening between the shutter members carried by the shutter shafts 12 and 8| may be varied between zero and 170, and this control may obviously be effected when the camera is in full operation. The scale I24 which indicates the degrees of shutter opening is visible from outside the camera through an arcuate glass window I in wall I3, with which the scale comes into register when the camera boxis in the position of Fig. 12. Preferably, the rear end of inner shutter shaft BI and the rear end of gear sleeve 00 on hollow shutter shaft 12 are provided with shutter signal devices I41 and I48, respectively, (Figs. 4 and '1). Member I41 is a circular disc, one half of which is painted black to correspond with the shutter opening of the shutter on the forward end of shaft 12, while member I465 which may be painted black all over, is of the same shape as the shutter leaf on the forward end of shutter shaft 6|. These shutter signal members register with a double glass walled window I49 in rear camera wall I3 (Fig. 2) when the camera mechanism is in the take position described, and indicate at a glance the positions of the two shutter members. Y

Thus when camera box 32 has been moved by operation of handle 60 to "take posit. an, the dissolve mechanism carried by said box comes into operative relation with a manual crank which is mounted in the rear exterior housing wall, and which may at that time be operatively engaged with the dissolve mechanism.

The dissolve mechanism also involves automatic devices for accomplishing the dissolve, which likewise register with control devices mounted in the rear camera case wall I3 when the camera box has been moved to the take" position illustrated in Fig. 12. The worm 9| on gear sleeve 90 meshes with worm gear I50 on a vertical shaft I5I (Figs. 7 and 8). Shaft I5I carries a spiral gear I52 which meshes with a spiral gear I53 on. a stud shaft I54, said shaft I54 also carrying a spur gear I55. Gear I55 meshes with a spur gear I56, which in turn meshes with another spur gear I51 directly over it.

Gear I56 is mounted to rotate on the inner end of a shaft I60 which is mounted to reciprocate through a bore I6I in casting 93 (Figs. 12 and 13) Movement of shaft I60 inwardly from the posi-' tion shown in Figs. 12 and 13 engages gear 156 with gear teeth I62 on the edge of vertically movable rack I I0 which is opposite to the previously mentioned rack teeth I20. Gears I55, I56 and I51 are of sufficient length relative to each other that gear I56 remains in mesh with the other two gears during such movement into mesh with the rack. It will be evident that when gear I55 is thus in mesh with rack gear teeth I62, the rack will be moved in a vertical direction, and will actuate the shutter dissolve mechanism in a manner similar to that effected when hand crank I40 is operated, as previously described. The rack is then being moved by power applied through the gear train from the rotating shutter shaft 12. The upper gear I51 is mounted on a shaft I10 (Fig. 7) which is longitudinally movable in a bore in casting 93, gear I51 having a peripheral groove I12 engaged by a fork I13 mounted on the inner end of control shaft I15 which is mounted for longitudinal reciprocation through a bore I16 in casting 93. Inward movement of shaft I15 from the position shown in Fig. 7 causes gear I51 to move inwardly into engagement with the rack teeth I62 of rack IIO, while remaining in mesh with its driving gear I56, and since gears I56 and I51 rotate in opposite directions, the rack is then moved in a direction opposite to that effected during the engagement of gear I 56 with the rack, thus causing automatic operation of the dissolve mechanism in a sense opposite to that effected by engagement of gear I56 with the rack.

To prevent the gears I56 and I 51 from being engaged simultaneously with the rack, there is provided a safety guard in the form of a pivoted yoke I60 (Figs. 9 and 13), the two arms of which have beveled ends III which engage conical surfaces I82 on shafts I60 and I15. The relative arrangement of the parts is such that in order for either of the two shafts to move inwardly to engage its gear with the rack, its conical surface I62 in engagement with the beveled end of the corresponding yoke arm must cause the yoke to swing to a position with the beveled end of its other arm moved into locking engagement with the inwardly inclined conical surface I92 of the other shaft. Thus but one of the two shafts can be moved inwardly at a time, inward movement 5 of either one of the shafts positively locking the other against similar movement.

It has been said that gears I55 and I51 are moved into mesh with rack II9 by virtue of inward movement oi shafts I69 and I15, respec- 10 tively. These shafts are normally yieldingly held in a rearwardly retracted position by means of coil springs I95 and I96, respectively, (Figs. '1 and 13) placed around the shafts in counterbores I91 and I99, and acting outwardly on the shaft 15 collars I99 and I99 which work within said counterbores.

The outer ends of shafts I69 and I15 are adapted to be actuated by actuating plungers I92 and I99, respectively, (Figs. 13 and 14) which are mounted to reciprocate through bores I99 and I99 in rear housing wall I3, and are located in said wall in such position that plungers I92 and I99 come into end to end register with shafts I59 and I15, respectively, when the camera box 92 25, is moved to photographing position (Fig. 12).

The inner ends of plungers I92 and I99 have enlarged heads I96 and I91, respectively, adapted to engage the adjacent ends of shafts I69 and I15, said heads being engageable against the inner surfaces of rear wall casting I3 to limit outward movement of the plungers. The plungers are normally yieldingly held in a position with heads I95 and I91 in such engagement with wall I9 (clearing the outer ends of shafts IE9 and I15) by means of coil springs 209 and 29I respectively, placed around said plungers in counterbores 292 and 299, and acting outwardly against shaft collars 299 and 295 which work within said counterbores.

On the outwardly projecting ends of plungers I92 and I99 are push buttons 296 and 291, respectively. It will be evident that normally there is no interference between shafts I69 and I15, and their actuating plungers I92 and I99, so that the camera box 92 is free of interference in its transverse shift; but that, when camera box 92 is in photographing position (Fig. 12), either of the plungers, say I92, may be moved inwardly by pressure of the finger on push button 296,

until the inner end of said plunger engages the outer end of its corresponding shaft i159 and moves the latter inwardly to engage gear I with rack II9, with the previously described resulting operation of the dissolve mechanism.

55 Upon release of push button 295, both members I99 and I92 return to their normal extended in operative position. Shaft I15 is similarly operated to engage gear I51 with the rack by p hing inwardly on pushbutton 291.

0 The means for locking the dissolve mechanism in such a way that relative rotation between the two shutter shafts cannot take place during normal o eration of the camera will now be de-- scribed in detail. For this purpose there is pro- 65 vided a locking plunger 229 (see Figs. 8, 10, 12 and 13) which is mounted to reciprocate in a bearing 22I, the latter extending through and being fastened to camera wall 92a in such disposition that the end of plunger 229 is immedi- 70 ately opposite the rear side of rack member H9. The forward end of plunger 229 is provided with horizontally cut teeth 222 (Fig. 10), which are adapted to engage similar horizontal teeth 229 (see also Fig. 8) cut in a vertical row on the ad jacent side of said rack. A coil spring 225 placed around plunger 229 and engaging a plunger shoulder 229 urges said plunger to move in a direction to engage its teeth 222 with rack teeth 229. It will be evident that this engagement, which may be made at any position of rack III, 5 positively locks the rack against vertical movement, and hence locks the entire dissolve mechanism adjustment means against operation. It will be evident, however, that this locking means does not lock the shutter mechanism against op- 10 eration, since the shutter shafts are left free to rotate, and sleeve I99 is free to rotate with said shaft; the mechanism is locked, however, against longitudinal movement of sleeve I99 on gear sleeve 99, which is the action causing relative is rotation of inner shutter shaft 9| with reference to hollow shutter shaft 12.

When the dissolve mechanism is to be operated for the purpose of changing the shutter opening, plunger 229 is withdrawn against spring 20 225 to disengage the rack for vertical movement. Plunger 229 carries for this purpose a plate 299, intooneend of which is screwthreaded a push rod 23I which is reciprocable through the aforementioned hollow shaft I22 and projects normally a short distance beyond the shaft head I29 (Fig. 12). When crank I99 is moved inwardly to engage crank pin I39 with aperture I29 for the purpose of accomplishing a manual dissolve, crank disc I92 engages the projecting end of push rod 29I and forces it inwardly, thereby moving plate 299 and locking plunger 229 to disengage said plunger with rack I99. This disengaged position is shown in Fig. 13. The rack is thus freed for vertical movement, and manual crank I99 may be turned to accomplish the dissolve mechanism desired. When crank I99 is released, it moves outwardly under the influence of its spring I99, and so releases push rod 29I and plate 299 to move outwardly under the influence 40 of locking plunger spring 225, which thereupon acts to move the locking plunger into engagement with the rack teeth to lock the dissolve mechanism against further shutter adjustment movement. 4:;

Locking plunger 299 is also moved inwardly to release the rack with inward movement of either shaft I99 or shaft I15 in meshing gears I55 or I51, respectively, with the rack. For this purpose shaft I69 has on its extreme inner end an 50 extension 295 (Fig. 13) adapted to engage plate 239 during its inward movement to move said plate and locking plunger 229 inwardly to disengage the rack for vertical movement. For the same purpose, gear I51 which is moved inwardly into mesh with the rack through inward movement of shaft I19 is provided with a projection 299 (Fig. 7) adapted to engage and move plate 299 during S 1011 inward movement, and so cause disengagement of the locking plunger with the rack, thereby freeing the latter for vertical movement.

It is thus seen that the present invention provides means which positively locks the shutter shafts against relative rotation with respect to each other during normal operation of the camera, and which thus positivelyprevents creep of the shutter members with reference to each other, and therefore uncontrolled variation of the shutter opening angle, and that this locking means, which is adapted to lock the shutter shafts at any shutter opening angle desired, is automatically disengaged and frees the shutter shafts for relative adjustment rotation by virtue of throwing either the manual or automatic shutter adjustment control devices into operative relation with the dissolve mechanism.

Reference is here made to my copending application entitled Shutter dissolve mechanism, filed 5 Dec. '7, 1935, Ser. No. 53,380, which contains claims to certain dissolve mechanism control devices herein disclosed.

While I have herein described one embodiment which the invention may assume in prac- 10 tice, it will be understood that it may assume other forms or be substantially modified without departing from the spirit and scope thereof or of the appended claims.

I claim:

15 1. In a shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment means for causing relative rotation of said shutter mem- 20 bers while they are being rotated by said shutter drive means, and manual means adapted to actuate said shutter adjustment means: movable positive locking means mounted independently of the shutter adjustment means and movable relatively to said means to enter into positive locking engagement therewith, said shutter adjustment means being adapted for positive locking reception oi said-locking means in varlous positions, and means for unlocking said locking means operated by actuation of said manual means to cause shutter adjustment operation.

2. In a shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment means for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, and manual means adapted to actuate said shutter adjustment means; movable 40 positive locking means mounted independently of the shutter adjustment means and movable relatively to said means to enter into positive locking engagement therewith, said shutter adjustment means being adapted for locking reception 45 of said locking means in various positions, yielding means normally holding said locking means in locking position, and means for unlocking said locking means against said yielding means operated by actuation of said manual means to 50 cause shutter adjustment operation.

3. In a shutter dissolve mechanism embody ing relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment means for 55 causing relative rotation of said shutter members while they are being rotated by said shutter drive means, and manually actuatable means adapted to actuate said shutter adjustment means: a movable positive locking member mounted for movement independently of the shutter adjustment means normally moved into a position of positive locking engagement with said shutter adjustment means to lock said means against shutter adjustment operation,

65 said shutter adjustment means being adapted for positive locking reception of said locking member in various positions, and means for mov-- ing said locking member to unlocked position operated by actuation of said manual means to 70 cause shutter adjustment operation.

4. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for 75 causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a member stationary during normal operation of the shutter members but movable to accomplish relative rotation of the shutter members, a positive locking member mounted independently of the shutter adjustment mechanism and movable into positive locking engagement with said normally stationary member to lock the shutter adjustment mechanism against adjustment operation, said normally stationary member being adapted for positive locking reception of said locking member in various positions, and manual means for moving said looking member out of locking engagement with said shutter adjustment member and thereafter actuating said shutter adjustment member.

5. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a member stationary during normal operation of the shutter members but movable to accomplish relative rotation of the shutter members, manual means for moving said shutter adjustment mechanism member, a movable positive locking member mounted for movement independently of the shutter adjustment mechanism and positioned normally in looking engagement with said shutter adjustment mechanism member, said shutter adjustment member being adapted for positive locking reception of said looking member in various positions, and means for disengaging said locking member from said shutter adjustment mechanism member actuated by virtue of actuation of said manual means.

6. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a member stationary during nor-, mal operation of the shutter members but.movable to accomplish relative rotation of the shutter members, manual means for moving said shutter adjustment mechanism member, a movable positive locking member mounted for movement independently of the shutter adjustment mechanism and adapted to be moved into positive locking engagement with said shutter adjustment mechanism member, said shutter adjustment member being adapted for positive locking reception of said locking member in various positions, yielding means urging said locking member into such locking engagement, and means for disengaging said locking member from said shutter adjustment mechanism member actuated by virtue of actuation of said manual means.

7. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive 79 means, said shutter adjustment mechanism including a member stationary during normal operation of the shutter members but movable to accomplish relative rotation of the shutter members, manual means movable into operative driving relation with said shutter adjustment mechanism member and operable to move said member, and a movable locking member normally in locking engagement with said shutter adjustment mechanism member, said locking member adapted to be moved to disengage said member by virtue of moving said manual member into driving rotation with said shutter adjustment mechanism member.

8. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a member stationary during normal operation of the shutter members but movable to accomplish relative rotation of the shutter members, shiftable means adapted to drivingly interconnect the shutter drive means with said shutter adjustment mechanism member to cause movement of the latter, a movable positive locking member normally in positive locking engagement with said shutter adjustment mechanism member, and means actuated by virtue of shifting said interconnecting means to drivingly interconnect the shutter drive means with the shutter adjustment mechanism member for disengaging said locking member from the shutter adjustment mechanism member.

9. A shutter dissolve mechanismembodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation 01' said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a member stationary during normal operation of the shutter members but movable to accomplish relative rotation 01 the shutter members, manually actuatable means for moving said shutter adjustment mechanism member, a positive locking member mounted independently oi the shutter adjustment mechanism and movable along a fixed path into positive locking engagement with said shutter adjustment mechanism member, said shutter adjustment mechanism member being adapted for positive locking reception of said, locking memher in various positions along the path of movement of said shutter adjustment mechanism member, and means for disenga ing said locking member from the shutter adjustment mechanism member as the manually actuatable means is actuated to cause movement of the shutter adjust ment mechanism member.

10. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a reciprocable rack gear stationary during normal operation or the shutter members but movable to accomplish relative rotation thereof, a locking plunger reciprocable at right angles to said rack gear and adapted to move into locking engagement therewith, a gear means for moving said rack gear, manual means 'drivingly engageable with said gear means, and means for disengaging the locking plunger from the rack operated by virtue of drivingly engaging said manual means with said gear means.

11. A shutter" dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter member in unison, shutter adjustment mechanism for cansing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a reciprocable rack gear stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, a locking plunger reciprocable at right angles to said rack gear and adapted to move into locking engagement therewith, a gear adapted to be moved into mesh with said rack, a driving interconnection between said gear and the shutter drive means, manual means for moving said gear into mesh with the rack, and means actuated by virtue of moving said gear into mesh with the rack for disengaging the locking plunger from the rack.

12. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter member in imison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a reciprocable rack gear stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof,

a locking plunger reciprocable at right angles to,

said rack gear and adapted to move finto locking engagement therewith, gear means ior moving said rack gear, said gear means including a hollow shaft rigid and concentric with a pinion gear of said means, manual means for rotating said hollow shalt, including a manually reciprocable and rotatable shaft concentric therewith, clutch means between the near ends 01 said shafts adapted to form a rotatable driving connection therebetween upon axial movement of the manually rotatable shai't toward the hollow gear shaft, and an inner shaft reciprocable through said hoilow gear shaft and connected with said locking plunger and adapted by axial movement to move said plunger out of engagement with the rack gear, said inner shaft normally projecting from the end of the hollow shaft to be engaged by the manually rotatable shaft and so moved to cause said disengagement oi the locking plunger from the rack gear when the manually rotatable shaft is moved axially to drivingly engage the hollow gear shaft.

13. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a reciprocable rack gear stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, said not gear formed with a longitudinally extending series of transverse teeth, a locking plunger reciproeable at right angles to said rack gear and adapted to move into locking engagement with said rack teeth, gear means ior moving said rack, and means or disengaging said locking plunger from the rack during drive of the rack by said gear means.

14. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by'said shutter drive means, said shutter adjustment mechanism including a rcciprricable member stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, said reeiprocablc member formed with a longiimiinally extending series of transversely cut teeth, a locking plunger reciprocable at right angles to the direction of reciprocation of said reciprocable member and adapted to move into locking engagement with said transverse teeth, and means for disengaging said locking plunger from said reciprocable member.

15. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a gear member stationary during normal operation of the shutter. members but movable to accomplish relative" rotation thereof, a movable locking member normally in locking engagement with said gear member, said gear member being adapted for locking reception of said locking member in various positions along the path of movement of said gear member, a driving pinion for moving said gear member, manual means drivingly connectible with said pinion. and means for automatically disengaging the locking member from the gear member when said manual means is driyingly engaged with said pinion.

16. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a gear member stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof,

a movable locking member normally in locking engagement with said gear member, said gear member being adapted for locking reception of said locking member in various positions along the path ofmovement of said gear member, a driving pinion adapted to be moved into mesh with said gear member, a driving interconnection between said pinion and the shutter drive means, manual means for moving said pinion into mesh with said gear member, and means actuated with movement of said pinion into mesh with the gear member for disengaging the locking member from the gear member.

1'7. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a gear member stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, a driving pinion for moving said gear member, manual means drivingly connectible with said pinion, a movable locking member normally in locking engagement with the shutter adjustment mechanism, the shutter adjustment mechanism being adapted for locking reception of said locking member in various positions of adjustment of said mechanism, and means for automatically disengaging the locking member from the shutter nism including a gear member stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, a driving pinion adapted to be moved into mesh with said gear member, a driving interconnection between said pinion and the shutter drive means, manual means for moving said pinion into mesh with said gear member, a movable locking member normally in locking engagement with the shutter adjustment mechanism, the shutter adjustment mechanism being adapted for locking reception of said locking member in various positions of adjustment of said mechanism, and means for automatically disengaging the locking member from the shutter adjustment mechanism when said manual means is drivingly connected with said pinion.

19. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment including a gear member stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, a driving pinion adapted to be moved along its axis into mesh with said gear member, a longitudinally movable shaft on which said pinion is journalled, said shaft adapted to be moved longitudinally to carry said pinion into and 'out of mesh with said gear member, a driving interconnection between said pinion and the shutter drive means, said interconnection including a. gear meshing with said pinion throughout axial movement of the latter with the longitudinally movable shaft, a movable locking member normally in locking engagement with the shutter adjustment mechanism, the shutter adjustment mechanism being adapted for looking reception of said locking member in various positions of adjustment of said mechanism, and means movable with the longitudinally movable shaft for retracting the locking member from engagement with the shutter adjustment mechanism when the shaft is moved to engage the pinion mounted thereon with the shutter adjustment gear member.

20. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism including a member stationary during normal operation of the shutter members but movable to accomplish relative rotation of the shutter members, manually actuatable means for moving said shutter adjustment mechanism member, said means including a normally disconnected driving train between the shutter drive means and the shutter adjustment mechanism and a manually controllable element for connecting said train, a

positive locking member mounted independently of the shutter adjustment mechanism and movable along a fixed path into positive locking engagement with said shutter adjustment mechanism member, said shutter adjustment mechaw nlsm member being adapted for positive locking reception of said locking member in various positions along the path of movement of said shutter adjustment mechanism member, and means for disengaging said locking member from the shutter adjustment mechanism member as the manually actuatabie means is actuated to cause movement of the shutter adjustment mechanism member.

21. A shutter dissolve mechanism embodying relatively rotatable shutter members, shutter drive means for rotating said shutter members in unison, shutter adjustment mechanism for causing relative rotation of said shutter members while they are being rotated by said shutter drive means, said shutter adjustment mechanism ineluding a gear member stationary during normal operation of the shutter members but movable to accomplish relative rotation thereof, means for operating said gear member including a hollow shaft and a gear mounted thereon meshing with spear is said gear member, manual means for rotating said hollow shaft, including a manually reciprocable and rotatable shaft concentric with said hollow shaft, clutch meansbetween the near ends of said shafts adapted to form a rotatable driving connection therebetween upon axial movement of the manually rotatable shaft toward the hollow gear shaft, a movable locking member normally in locking engagement with the shutter adjustment mechanism, the shutter adjustment mechanism being adapted for locking reception of said locking member in various positions of adjustment of said mechanism, an inner shaft reciprocable through said hollow shaft and operatively connected with said locking member and adapted by axial movement to move said member out of locking engagement with the shutter adjustment mechanism, said inner shaft normally projecting from the end of the hollow shaft to be engaged by the manually rotatable shaft and so moved to cause said disengagement of the locking member from the shutter adjustment mechanism when the manually rotatable shaft is moved axially to drivingly engage the hollow gear shaft.

GEORGE A. MITCHELL.

CERTIFICATE OF CORRECTION.

Patent No. 2,088,715.

August 5 957 GEORGE A. MITCHELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Page 5, first column, line 14.14., claim 2, before thetword "locking," insert positive;a.nd

that the said Letters Patent should be read vvith this correction there in that the same may conform to the record of the case inthe Patent Ofrice.

Signed and sealed this 19th day of October, A. D. 1957.

(Seal) Henry Van Arsdale. Acting Commissioner of Patents. 

